Pump

ABSTRACT

The present invention comprises a pump ( 10 ) having a casing ( 14 ) with at least one first hermetically sealed chamber ( 19 ) and at least one second chamber ( 17 ) adjacent to said first chamber, defining a passageway ( 18 ) for fluids and having an inlet ( 15 ) and an outlet ( 16 ) for the fluids. The stator ( 12 ) is provided in this first chamber ( 19 ). In addition, a rotor-turbine assembly ( 11 ) is induced by the stator ( 12 ) to drive a fluid from the inlet ( 15 ) to the outlet ( 16 ), the rotor and the turbine being integral and wholly located in the second chamber ( 17 ).

[0001] The present invention relates to a pump, more specifically, ahydraulic one.

DESCRIPTION OF THE PRIOR ART

[0002] At present, there are different types of electromechanical pumpsused for driving fluids, generally constituted of a chamber containingthe electromagnetic part, basically comprising the stator and the rotorarmature, as well as another chamber with a hydraulic part, basicallyformed of the hydraulic turbine that drives the liquid. However, theelectromagnetic and hydraulic chambers need to be insulated from eachother so as to prevent the liquid from reaching the stator and therotor, causing short-circuits and even irreparable damage. Thus, inorder to achieve this insulation of the chambers and transmission ofrotation movement from the rotor to the hydraulic turbine, severalmechanical apparatus are required, such as an axle, roller bearings,bearing journals, cooling systems, hydraulic seals, among others.

[0003] The roller bearing journals, for instance, have the function ofsupporting the rotor axle, on which the rotor cage is mounted, so that,when the latter is induced by magnetic forces from the stator, the rotorturns, assisted by these bearings. Of course, the journals arelubricated with oil or grease so as to decrease friction and wearbetween the parts in contact.

[0004] One end of the rotor axle is connected to the hydraulic turbine,formed of blades, which, upon induction of the rotor, begins arotational movement driving the liquid to be pumped.

[0005] To prevent the temperature of both the stator and the rotor fromreaching undesired levels during their functioning, external coolingsystems are used, usually constituted of ventilators. Such coolingsystems generally comprise propellers coupled to the end of the rotoraxle, outside the pump and opposed to the hydraulic pump, which, takingadvantage of the rotation of the rotor, turns to cool both the statorand the rotor.

[0006] The pumps of the prior art depend upon the perfect functioning ofthe mechanical seals to prevent the liquid from passing from thehydraulic chamber into the electromagnetic chamber. As alreadymentioned, this undesirable contact of the liquid with the stator androtor may cause short-circuits, as well as a decrease in the lubricationof the journals, resulting in possible seizure of the rotor.

[0007] Therefore, one can verify the fact that the prior art pumps havehydraulically insulated chambers, wherein an induced, rotor located in ahermetically sealed chamber, transmits rotation by means of its axle toa hydraulic turbine located in another liquid-passage chamber, making itnecessary for these pumps to have a number of sealing mechanisms toprevent the occurrence of damage that might even render them useless. Inaddition, with use the consequent wear of these mechanisms, such pumpslose their mechanical efficiency. Thus, this combination has thedrawback of entailing high costs, because it involves expensive parts, acomplex manufacturing process and constant maintenance to keep suchpumps functioning.

[0008] In view of this, the main objective of the present invention isto simplify the composition of a traditional pump by eliminatingsealings, such as mechanical seals or gaskets, as well as rollerbearings, axles and external cooling systems, such as ventilators,thereby reducing the chance of the pump being damaged. This new pumpmotor further provides cooling of the stator-rotor assembly bycirculating the pumped fluid itself, as described in patent applicationPI 0004206-4.

[0009] In addition, the invention also has the objective of providing anew pump that is more compact than the present ones, easy to manufactureand assemble, by virtue of its smaller number of components, thusresulting in better automation and cost reduction.

[0010] Another objective of the present invention is to provide a pumpthat is more efficient, that is, presenting lower energy loss.

[0011] In addition, the invention aims at providing a safer, moreprotected and corrosionproof pump motor, enabling immersion andinstallation in environments that are aggressive and without cooling.

[0012] A further objective of the present invention is to provide a pumpwith a very low noise level and lubrication provided by the circulatingfluid itself.

SUMMARY OF THE INVENTION

[0013] The present invention achieves all these objectives by means of apump comprising a casing, having at least one first hermetically sealedchamber and at least one second chamber adjacent to said first chamber,provided with a fluid passage and having an inlet and an outlet forfluids. Said chambers are separated by means of walls, preferably madeof injected polymer.

[0014] The pump further comprises a stator located in the first chamber.In a preferred embodiment, the stator is in a position adjacent to thewalls that separate the first chamber from the second, so that the fluidcirculating through the second chamber will cool it by heattransmission.

[0015] An integral rotor-turbine assembly, wholly located in the secondchamber, is provided, and at least a portion of said assembly ispositioned concentrically in relation to the stator. This assembly isinduced by the stator to drive a fluid from the inlet to the outlet.When the pump is functioning, at least a fluid film is maintained aroundthe assembly, in order to bring about perfect rotation with minimumfriction and without any need for journals. The space between saidassembly and the stator, called a gap, is substantially filled with saidwalls of the first and second chambers, including, furthermore, thefluid film circulating between them.

[0016] A metallic component, called the rotor cage, preferably composedof iron and aluminium, capable of being induced by the stator, isprovided inside the hermetically sealed assembly. In the preferredembodiment, such an assembly is made from polymeric material and isadditionally bored through to provide a passage for the turbine insidethe rotor. In possible embodiments of the present invention, the turbineof said assembly is composed of turbine blades to centrifuge the fluids.In this way, upon functioning of a possible embodiment of the pump, thefluid, after passing through the inlet of the second chamber, goes intothe rotor-turbine assembly, passes through the internal passageway and,after reaching the turbine blades, is driven towards the outlet.

[0017] However, a portion of the fluid, instead of coming out directlythrough the outlet, circulates around the first chamber and cools thestator by heat transmission. In this way, the need for an externalcooling system is eliminated, since the heat exchange between thecirculating fluid and the driving assembly will result in cooling thisassembly, so that its temperature will always remain at desirable levelsfor its good functioning.

[0018] In addition, the circulating fluid is also used as a lubricant. Afilm of circulating fluid will pass between the walls of the secondchamber and the rotor-turbine assembly, allowing the latter to make afloating rotary movement within the second chamber by virtue of theinducing forces.

[0019] In view of the foregoing, the pump of the present inventionprovides a simpler configuration with less expensive manufacture, sinceit is basically composed of an induction means and amovement-transmission means similar to those of the prior art, such asstators and rotors, which eliminate the use of a ventilator, as well asroller bearings, axles and mechanical seals.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will now be described in greater detailwith reference to the drawings.

[0021]FIG. 1 is a cross-section side view of a typical pump motor of theprior art; and

[0022]FIG. 2 is a cross-section side view of the device for drivingfluids of the present invention.

DETAILED DESCRIPTION OF THE FIGURES

[0023]FIG. 1 shows a present-day pump, encountered in the prior art,comprising a coiled stator 4, a rotor 5 and roller bearings 3, whichsupport the axle 9 on which the cage of said rotor 5 is mounted. Theaxle 3 will be responsible for transmitting driving force from the rotor5 by means of induction of the magnetic field of the stator 4. One canalso note in this figure the existence of a ventilator 1, which isresponsible for cooling the stator-rotor assembly, and of covers 2located on both sides of the rotor 5, which support said rollerbearings.

[0024] In addition, in order to achieve a good functioning of this typeof pump motor, the rotor 5 has to be perfectly centered with respect tothe stator 4, so as to avoid contact between their magnetic iron. In thepump motor represented in FIG. 1, this space between the rotor 5 and thestator 4, called a gap, is filled with air.

[0025]FIG. 1 further illustrates mechanical seals 8, which are widelyused in the pump motors of the prior art, to guarantee ventilation andseparation between the electric part and the hydraulic part of the pumpmotor, the hydraulic part being constituted of the turbine 7 and thevolute 6.

[0026]FIG. 2, on the other hand, illustrates a preferred embodiment ofthe present invention, in which some of the elements shown in FIG. 1 areabsent. This embodiment illustrates a pump 10 comprising a casing 14having a first hermetically sealed chamber 19 and a second internalchamber 17 with at least one inlet 15 and one outlet 16 defining thepassageway 18 between said inlet and outlet. The casing 14 may be madefrom a polymeric material or any other type of material suitable for thespecified conditions, including bad weather.

[0027] An integral rotor-turbine assembly 11 is located in the chamber17 to drive the fluids that pass through said chamber. This assembly ismade from a polymeric material and, in addition, is bored through todefine a passageway for the turbine inside the rotor. In thisembodiment, the turbine of said assembly is composed of blades forcentrifuging the fluids. In this way, when in operation, the fluid,after passing through the inlet 15 of the chamber 17, goes into therotor-turbine assembly 11, passes through the internal passageway, and,after reaching the turbine blades, is driven toward the outlet 16.

[0028] The casing 14 also has a first chamber 19, hermetically sealedfrom the fluids that circulate through the second chamber 17. Both theexternal walls of the casing and the walls that separate the secondchamber 17 from the first chamber 19 are formed of injectable polymericmaterial. In addition, the stator 12, which may be any one of thoseknown from the prior art, is installed in this first chamber 19 toinduce, by means of a magnetic field, the driving of the rotor-turbineassembly 11, located in the second chamber 17 of fluid circulation.

[0029] This embodiment of the pump of the present invention also has itssecond chamber 17 defining passageways other than that going from theinlet to the outlet, so that a portion of the fluids will circulatethrough this chamber. Such passageways in this embodiment cause thefluid to circulate around the first chamber 19, cooling the stator 12located therein by heat transmission.

[0030] In addition, a small portion of the fluid that enters inlet 15and circulates through the second chamber 17 passes through thecommunication means 13 between one of the walls of the second chamber 17and the rotor-turbine assembly 11, creating a constant fluid film, whichenables this assembly to turn freely submerged in the liquid, withouthaving any contact with the walls of the second chamber 17 while thepump is functioning. In this way, such a film acts as a support for theassembly 11 and, at the same time, as a lubricant that virtuallyeliminates friction between the walls of the second chamber and of theassembly 11, further resulting in a very low noise level. Although theassembly 11 is submerged in the liquid, without contact with the wallsof the second chamber 17, the magnetic field created by the stator 12maintains the former in a balanced position around its axle, so that,upon rotational movement, the magnetic forces prevent the assembly fromcontacting the walls of the second chamber 17.

[0031] In view of the foregoing, since the second chamber 17 haspassageways that enable the liquid to circulate through it, a reductionin noise level is achieved, and this also eliminates the need forindustrial lubricants and external cooling systems. Since the pump isbasically composed of an injectable polymeric material and there is adecrease in the number of components (i.e. does not include seals) incomparison with those of the prior art, it becomes simpler and lessexpensive to assemble. In addition, the energy losses are minimised bythe low friction between the rotor-turbine assembly 11 and the walls ofthe second chamber 17.

[0032] Another important aspect of the present invention is that thespace between the stator 4 and the rotor 5 of the pumps of the priorart, the so-called gaps, are filled with air. In the present invention,on the other hand, in addition to the liquid layer 13, there is thepolymeric wall of both the second chamber 17 and the rotor-turbineassembly 11, guaranteeing a perfect centering of the magnetic materialsof the stator 12 and the assembly 11, as well as a better balancedposition of the latter around its axle, so that, upon rotation, contactwith the walls of the second chamber 17 will be avoided.

[0033] In addition, the present invention also provides a non-corrosivepump, since only the surface covered with polymer will have contact withthe fluid. Therefore, the latter may be aggressive without causing anydamage to the pump motor. In addition, since the liquid itself is usedas a coolant, the pump of the present invention may be installed inenvironments without ventilation or even submerged.

[0034] Having described an example of a preferred embodiment of theinvention, it should be understood that the scope of the presentinvention embraces other possible variations, being limited only by thecontents of the accompanying claims.

1. A pump (10) comprising: a casing (14) having at least one firsthermetically sealed chamber (19), and at least one second chamber (17)adjacent to said first chamber, defining a passageway (18) for fluidsand having an inlet (15) and an outlet (16) for the fluids, the firstand second chambers being separated from each other by walls; a stator(12) located in said first chamber (19); a rotor-turbine assembly (11)capable of being induced by the stator (12) to drive a fluid from theinlet (15) to the outlet (16), at least a portion of said assembly beingpositioned concentrically with respect to the stator, characterized inthat the rotor and the turbine are integral and are wholly located inthe second chamber (17), so that, when in operation, at least a film offluid (13) will be maintained around said assembly (11).
 2. A pump (10)according to claim 1, characterized in that said rotor-turbine assembly(11) is bored through, defining an internal passageway for the turbinein the rotor.
 3. A pump (10) according to claim 1 or 2, characterized inthat said walls of the first (19) and second (17) chambers are made ofinjectable polymer.
 4. A pump (10) according to any one of claims 1-3,characterized in that said rotor-turbine assembly (11) is of a polymericmaterial, having a metallic component inside, which is capable of beinginduced by the stator (12).
 5. A pump (10) according to claim 4,characterized in that said metallic component is composed of iron andaluminum.
 6. A pump (10) according to any one of claims 1-5,characterized in that said stator (12) is located in a position adjacentto the walls that separate said first (19) chamber from the said second(17), so that the circulating fluid can cool it by heat transmission. 7.A pump (10) according to any one of claims 1-6, characterized in thatthe turbine of said assembly is composed of blades for centrifuging thefluids.
 8. A pump (10) according to any one of claims 1-7, characterizedin that the space between said assembly (11) and the stator (12) issubstantially filled up by said walls of the first (19) and the second(17) chambers.